Grandmother Val Joyce is up at 4.45am every weekday in time for her cleaning job.

She starts early so she can be back at her home in Clayton, Bradford, early enough to look after her three-year-old granddaughter Emily.

The 65-year-old is one of a growing army of granny-nannies stepping in as childminders for their own children's children.

A study by Skipton Building Society has revealed that two out of three families, in which both parents work, rely on grandparents' goodwill to do some childcare.

Val and her 69-year-old husband Philip look after their granddaughter and their 11-year-old grandson Andrew when he finishes school at Trinity & All Saints School in Bingley.

It allows their daughter Mary, 34, and son-in-law Christopher, 39, who live in the town, to work full time.

Val is a typical example of a granny-nanny in that over a third juggle full or part-time work with caring for the little ones.

The survey showed that more people in Yorkshire - 73 per cent - relied on granny-nannies than anywhere else in the country and saved on average £2,115 a year.

It also revealed that without grandparents coming to the rescue, half of working parents would be forced to live on a tighter budget.

One in five women said without the help they would not be able to afford to return to work.

And two thirds of the 1,000 adults surveyed liked the assurance of knowing their child was in a loving environment.

They also believed that grandparents could be relied upon and that good old-fashioned family values would be passed on. Val, who has looked after Andrew since he was four-months-old, said: "I wouldn't want to think that the children have to go to a childminder because we give them more loving care than anyone else.

"And the grandchildren love us so much. They tell us. Andrew is not afraid of telling us and giving us a kiss and a hug."

She had volunteered to look after the children when her daughter had said she was worried about being able to afford to give up work to have children.

"I couldn't bare to think how much she would have to pay out. I know some young women pay out hundreds of pounds," said Val who has nine grandchildren and five great-grandchildren and helped look after most of them.

Jennifer Holloway, of Skipton Building Society, said cost savings for parents using grandparents as carers was substantial.

A nursery place could cost up to £8,000 a year.